FRP helical reinforcement has been used to improve the ductility and confinement of the compression zone and thus provide increased flexural capacity of concrete beams (Taniguchi et al, 1993). FRP helices also function as shear reinforcement. This paper presents the findings of research conducted using continuous fibre helical transverse reinforcement, as a means to improve shear capacity. Circular helices located entirely in the compression zone and rectangular draped stirrups have been investigated. Twelve tests were conducted on beams using medium to high strength concrete and reinforced with 7.7 mm diameter Arapree tendons. Tests using Kevlar 49 sheathed ropes in continuous lengths as draped stirrups have shown encouraging results. The main concern using continuous lengths of unbonded rope is the large strains required to activate the fibres in an effective manner. However, tests have indicated that sufficient friction can be developed in the fibre-sheath-concrete system, such that each stirrup leg can develop near full tensile strength. Enhanced shear capacity has been achieved by varying the geometry of the continuous stirrups to ensure near-to-full strength contribution from the Kevlar rope. The easiness in which FRP reinforcement can be handled "on site" in comparison to steel reinforcement, is one of the major benefits provided by using advanced composites. In addition, continuous flexible reinforcement can be shaped "on site" and formed into almost any geometrical configuration.
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